Abstract: Abstract: In recent years, many porphyry-type Cu deposits have been found in Mongolian Gobi-Tianshan and in Chinese Beishan and Tianshan. This paper summarizes geological characteristics and metallogenic age data of typical porphyry-type deposits in these areas and suggests that the deposits were mainly formed during Devonian-Carboniferous. Meanwhile, most of these deposits are genetically related to adakites, indicating that they were formed in a volcanic arc setting. It is held that the deposits in these areas likely constitute a single giant porphyry-type metallogenic belt, which straddles the border between China and Mongolia. The features are analogous to features of the porphyry deposits in Neocene, implying great resource potential of CAOB (Central Asian Orogenic Belt).